At age 12, Kavita Shukla started working on what became her company's food-preserving FreshPaper.

The R&D for Kavita Shukla's company, Fenugreen, cost little more than a kid's science project — which, in fact, it was. At age 12, Shukla visited India, where a cup of her grandmother's homebrewed spice tea seemed to help her stave off the ill effects of accidentally drinking tap water. Returning home to Maryland, she spent several years trying to re-create that benefit, mixing kitchen spices in jars of pond water and then applying them to produce. “I was this weird kid with rotting strawberries in my garage,” says Shukla, now 30.

Eventually she came up with the idea of infusing the spices into sheets of paper; she even created her own paper blend, using $25 worth of materials from a craft store. Now Fenugreen, based in Columbia, Maryland, makes a product that is at once humble and potentially transformative: spice-infused FreshPaper, which keeps food fresh by inhibiting bacterial and fungal growth.

Shukla worked on her product throughout high school and college, investing her own money along the way. At 17, she spent $1,500 (won at science fairs) to obtain a patent, saving on legal fees by filing for and defending it herself. But when she got to Harvard, her attempts to create a global nonprofit couldn't get enough interest from potential donors and ultimately proved, well, fruitless. “I wanted to build a manufacturing facility to get FreshPaper to the developing world,” says Shukla. “But that didn't go anywhere.”

Since she couldn't find funding for a large-scale nonprofit, in 2011 she decided to try bootstrapping a local for-profit. Shukla and her co-founder, Swaroop Samant, spent around $150 on spices and papermaking materials to manufacture a thousand sheets of FreshPaper in the kitchen of Shukla's studio apartment. They offered the first samples to vendors at a farmers' market down the street. Then they pitched the Harvest Co-Op in Cambridge, Massachusetts, where “one of the directors said, ‘I bet if you bag this up, people would be interested in buying it,’” says Shukla. “I couldn't even imagine that consumers would be willing to pay for it.”

She and Samant invested around $50 to register as vendors at the farmers' market, and borrowed a card table and spent another $100 on a tablecloth, display baskets, a market umbrella, and a signboard. That first day they made $600; they were greeted by lines every time they went back.

FreshPaper was in a handful of co-ops and farmers' markets by 2012, when Whole Foods placed a big order for two regions. Today the product is sold in groceries nationwide, and in more than 35 countries — fulfilling Shukla's global aspirations. At some stores, for every pack of eight sheets sold, Fenugreen donates one pack to a U.S. food bank. (A pack retails for $5.99 and preserves $50 to $70 worth of produce.) Fenugreen is also evaluating collaborations with international NGOs working with farmers in the developing world to improve crop yields.

Interest from investors is strong, but Shukla prefers to go it alone for now, so Fenugreen can concentrate on social mission — not always the top priority for VCs. Robust sales to retailers and online customers has allowed it to do so. “We went to the farmers' market because it was all we could access,” says Shukla. “It's so incredible, this power of putting innovation right in the hands of the end user.”